I think if you brought well and did the trip on a budget (and without 3 kids...) then it could be easy to go cost neutral. But for us we will be backwards by a fair bit I think.
Knowing what we know now there would be a few things we would do differently but still very happy with how its gone so far.
The reality is that its a very easy trip to do and as BP says its a well trodden path. We havent even tacked yet in almost 8000nm of sailing!
We have met other kiwis doing it very comfortably in 100k 15 year old beneteaus and all types.
I just think that anyone who is thinking about it should do it soon.
The NZ boat market will be flooded with bigger second hand production boats soon.
Also who knows if piracy and corruption will just make it to risky to do in 5 or 10 years?